IRC/ACCC/ACUC confusion

[Tarun Nagpal]

Been really struggling with the HVAC blocks and getting them to work with my Fujitsu minisplits

Currently we are just using the VRF blocks
1. They don't actually respond to current temp correctly; e.g.
Set to cooling and they keep blowing cold air even when the target temp is above the current temp (e.g. target = 71; temp is 69 - keeps blowing cool air)

2. No scheduling sucks

When we set the minisplits up for IRC -> AC Central Controller -> AC Unit Controller using the API connections; everything goes to hell. It is almost different each time; one time we couldn't do anything besides set temps to the floor of 41 degrees across all comforts, target temps sometimes carry through, sometimes don't, the VRF sees the IRC sometimes, sometimes it doesn't.

When the three blocks seem to be in sync, then they don't seem to talk to the minisplit.

I am sure it is something small, but honestly it has been super annoying.

I guess I could just wire everything and ignore the API connection and see if that works, but is that really the right route?

Thanks!

[Jonathan Dixon]

I can't help much, as a minimum would more details about the steps already tried (Config screenshots etc). And not sure what you mean by "using VRF blocks"?

FWIW The HVAC controller declares itself intended for the "North American Market" so depending on your location & models used it may or maynot be the path of expected least resistance. Hence I've never experienented with it (I'm in the UK).

In my experience mini-splits work fine with AC Unit Controller but really intended for use with the Loxone Air AC interface boxes. Note that when it is in comfort mode it is "working by design" to leave the fan blowing even after target temperature reached, which sounds like what you saw with HVAC controller? See https://www.loxone.com/enen/kb/ac-control/ "Combining AC Unit Controller and Intelligent Room Controller": 

In Comfort Mode, the air conditioner maintains the desired temperature with minimal noise. If the comfort temperature is exceeded, it automatically begins cooling. Once the desired temperature is reached, it runs consistently at a low level to maintain the temperature. Comfort mode is intended for times when someone is in the building.

Getting the API connectors right is key for them to work at all, you should see IRC connected to both the ACCC and the ACc, and also an interconnection between the ACc and ACCC. Like so:

 

Depending what hardware you're using to connect to the AC, you can also forgo all these options (i.e. don't use HVAC controller nor the AC Unit Controller) and just pair the IRC to a Heating/Cooling controller, and wire the outputs of that direct to your interface device. In my experience this approach gives you (the Config programmer) the greatest level of control.  I've done it that way when using CoolAutomation hub, and it's also what the Loxone partner training suggested as the best place to start for AC systems. YMMV

HTH

 

--
You received this message because you are subscribed to the Google Groups "Loxone English" group.
To unsubscribe from this group and stop receiving emails from it, send an email to loxone-englis...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/loxone-english/7d5a8db1-a90a-4db8-8aa0-bdbdd5d44e7bn%40googlegroups.com.

[tarun]

After a lot of looking around I think it was from the limits being still in Celsius numbers despite my Loxone being set to Fahrenheit. So they were set at 15 and 19 degrees.  

Should I feed expected temp to the ACCC and current outdoor temp to the IRC? 

[Jonathan Dixon]

On Tue, 31 Mar 2026 at 10:10, tarun <tarun-...@nagpal.info> wrote:

After a lot of looking around I think it was from the limits being still in Celsius numbers despite my Loxone being set to Fahrenheit. So they were set at 15 and 19 degrees.  

Should I feed expected temp to the ACCC and current outdoor temp to the IRC? 

It shouldn't hurt if you do, but if everything is setup correctly you don't need to do this:

- the target temp will automatically propagate into ACCC from whichever IRC it is bound to. (btw It can only be bound to one IRC, even though Config allows you to connect it to multiple IRCS -- much to my disappointment as I had a project with AC units shared between rooms via electronic duct dampers)

- if the "Outdoor Temperature" system variable is  correctly, it will automatically be used by IRC

 

To view this discussion visit https://groups.google.com/d/msgid/loxone-english/788c2b3b-9b61-4f9f-94b9-6199b5c54385n%40googlegroups.com.

[tarun]

Sorry I wasn’t clear. 

Do I feed expected outdoor temp for the next 48 hours to the ACCC and current outdoor temp to the IRC?

[Jonathan Dixon]

Again, you can do but you don't need to, so long as the relevant System Variables are being populated with the correct values those things will grab them directly from that.

IRC:

ACCC - needs Otm setting to '2' to use the system variable:

To view this discussion visit https://groups.google.com/d/msgid/loxone-english/d564b689-ec9e-4f26-90d8-2f730d631dc3n%40googlegroups.com.

[Tarun Nagpal]

Got it - I sort of wish there was a visual indicator that it was getting a value from somewhere... but that is useful to know

Now with Config 17 - they expanded the IRC block functionality, but it is unclear to me what they mean by it - does the new IRC block replace the stack of three? They sort of imply that it does, but it doesn't really look like it.

And then the XMLs use completely different nomenclature than the config app which is hellish to deal with as well. 

Config crashes when I try and apply a preset but maybe it is the VM I am running Windows in because they don't have a Mac config app. 

Anyway, eventually I will get this working properly... But they don't have to make it so exhausting.

[Jonathan Dixon]

On Wed, 1 Apr 2026 at 17:11, Tarun Nagpal <t.na...@gmail.com> wrote:

Got it - I sort of wish there was a visual indicator that it was getting a value from somewhere... but that is useful to know

Yeah It is annoying when global variables are depended on in this opaque way. They've generally improved this over time (e.g. Operating Modes now list all schedule blocks that reference them) but there's still a lot of hidden connections.

For this one specifically, it's not so obvious but there is, kinda workaround:  if you enable the input live view will show you the value it is implicitly picking up when if it's not connected.

 

Now with Config 17 - they expanded the IRC block functionality, but it is unclear to me what they mean by it - does the new IRC block replace the stack of three? They sort of imply that it does, but it doesn't really look like it.

Yeah I thought the same as you at first. I had a quick poke around at it yesterday and don't think it actually is replacing the stack, as the IRC doesn't have any new output references to connect fan speed & mode etc to. So AFAICT it's just a UI consolidation to put pull together all those UI controls in one place in the app.  If (and only if) the IRC is linked to an ACc on the backend, it would presumably show the Fan control settings.  While still a faff in Config, this is much better UX as previously you had to surface both the IRC and the ACc in the app if user wanted to be able to edit fan speed/direction which added a lot of extra clutter.

And then the XMLs use completely different nomenclature than the config app which is hellish to deal with as well. 

Config crashes when I try and apply a preset but maybe it is the VM I am running Windows in because they don't have a Mac config app. 

I honestly haven't found a use case for Presets in a domestic setting.... it's too cumbersome to manage them in Config.  YMMV

To view this discussion visit https://groups.google.com/d/msgid/loxone-english/61b39b7b-61eb-4f00-b47e-6448866f5b3cn%40googlegroups.com.